Zeroizing means



C, F. \NEBB March 14, 1939.

ZEROIZING MEANS Filed NOV. 25., 1936 Patented Mar.. 14, 1939 UNITED` STATES LiSiLtii PATENT caries assigner to Bell Puno h Company Limited, lionn den, England, a British company Application November 25, 1936, Serial No. 112,640 In Great Britain February 28, 1936 7 Claims.

This invention relates to means for zeroizing the numeral wheels of registering, counting or other like mechanism and has for its object to provide improved Zeroizing means which are more simple in construction and more certain in operation than means of this kind hitherto proposed.

According to the invention the zeroizing means comprises in combination, a projection carried on one side of the numeral wheel and radially displaCed from the axis of the latter, and a lever provided with a pair of noses, which lever when actuated either causes one of the noses to engage with the projection on the numeral wheel so as to rotate the latter into the Zero position where its movement is arrested by the other nose engaging with the said projection, or causes the simultaneous engagement of both noses with the aforesaid projection so as to hold the wheel in the zero position thereof.

In a preferred construction of the zeroizing means according to the invention, the axis of the numeral wheel is disposed between the paths of movement of the noses of the lever.

The invention will be more particularly described with reference to the registering mechanism of taximeter which is illustrated purely by way of example in the accompanying drawing in which:

Figure l illustrates in side elevation a numeral wheel associated with zeroizing means constructed in accordance with the present invention;

Figure 2 is an end elevation of the mechanism illustrated in Figure 3, but with the window and the housing removed, and

Figure 3 is a view similar to that shown in Figure l, but with the numeral Wheel moved into the Zero position thereof.

Referring to the drawing, only those portions of the registering device of the taximeter which are essential to the present invention are illustrate-d Atherein, the remainder being obvious to anyone skilled in the art. The device comprises numeral Wheel l mounted upon a spindle 2 which carries a ratchet wheel 3 operable by a thrust pawl connected at the end remote from the ratchet wheel 3 to one end of a lever 5 pivotally .ed by a spindle ii, the lever 5 being shaped at the end remote from the pawl 4 in a manner and for a purpose hereinafter described. The lever 5 is arranged to be actuated by a driving cam l rotatable by a Worm wheel 8 and a worm t driven by the mechanism which operates the device. The ratchet wheel 3 of the registering device is provided with a spring actuated detent pawl 2U which, as the ratchet wheel 3 is moved lever I5, the lever I5 being carried by a spindle ES and being so arranged that one end I? lies in the path of the cam I3 whilst the other end is provided with a pair of noses 24, 25 for the purpose hereinafter described. The lever I5 is mounted adjacent to and in a plane parallel to the numeral wheel I and on one side of the latter is carried a freely rotatable roller I8, the arrangement being such that as the lever I5 swings about the axis of the spindle I6 the free end thereof engages with the roller i8 and moves the numeral wheel I into a position in which the zero index is arranged opposite to a window formed in the casing I9 of the housing of the device.

The operation of the device is as follows:

When the device is set in operation the worm e ldrives the worm wheel 8 and thereby rotates the cam l about ie axis of the worm wheel 8 in a counter-clockwise direction. The cam 'I upon each rotation thereof rocks the lever 5 about the axis of the spindle 6 and causes the thrust pawl 4 to move outwardly until under the influence of the spring 2l it engages the next succeeding tooth of the ratchet wheel 3, whereupon the lever 5 snaps back under the influence of spring 2l@ towards the axis of the worm wheel 8 causing the pawl 4 to eiiect an advance in registration of numeral wheel I.

When it is desired to restore the numeral wheel to its Zero position the spindle i4 is operated by the lever i5 will engage with the roller I8 in any position which the roller may have assumed prior to the resetting of the device and the interengagement of the lever I5 and roller I8 tends to move the Wheel I (through the medium of the roller i8) about the axis thereof so as to bring -lil the zero index opposite the window in the casing I9. When the cam I3 is rotated about its axis so as to permit the operation of the lever I5 it also engages with the lever II and rocks the latter about the axis of the spindle I2 so as to cause the end of the lever II remote from that end which engages with the cam I3 to move into engagement with the lug I9 on the lever 5 and thereby withdraw the pawls 4 and 20 out of engagement with the ratchet wheel 3 in the manner indicated in Figure 3 of the accompanying drawing.

The profile of the cam I3 is such that during the resetting operation the movement of the lever I5 is effective only after the withdrawal of the pawls 4 and 2B from their operative positions. Similarly, when the spindle I4 is returned to its original position as shown in Figure 1 the profile of cam I3 ensures that the pawls 4 and 20 are brought back into engagement with the ratchet 3 before the lever I5 is moved out of engagement with the roller I8.

As shown in the drawing the nose 25 is made to extend a greater distance laterally of the lever I5 than the nose 24. This is to prevent the simultaneous engagement of both noses with the roller I8 in any position of the latter other than that shown in Figure 3. Thus if the numeral wheel has been rotated through approximately from the position shown in Figure 3 so that the roller I8 is situated on the opposite side of the spindle 2 the nose 25 will first engage the roller I8 and rotate the wheel I towards the zero position; if the noses were made of substantially the same size there would be danger of the device jamming when the wheel occupied the position above envisaged.

I claim:

1. In a taximeter, the combination of a numeral wheel, a projection carried on one side of the numeral wheel and radially dispaced from the axis of the latter, a manually rotatable spindle. a cam on said spindle, and a spring urged lever engageable with said cam and having one end shaped to form a pair of noses so that on rotation of the cam by the spindle the lever is released and is swung by its spring to engage one of its noses with the projection aforesaid whereby the numeral wheel is rotated into the zero position wherein the other nose also engages the projection.

2. In a taximeter, the combination of a numeral wheel. means for intermittently rotating said numeral wheel, a projection carried on one side of said numeral wheel and radially displaced from the axis of the latter, a manually rotatable spindle, a cam on said spindle, a spring urged lever engageable with said cam and having one end shaped to form a pair of noses, one of said noses being arranged to engage the projection, on release of the lever by the cam, so as to rotate the numeral wheel into the zero position wherein the other nose also engages the projection, and a second lever engageable with said cam and operable, immediately before the release of the first-mentioned lever, to disconnect the numeral wheel rotating means from the numeral wheel.

3. In a taximeter, the combination of a numeral wheel, a projection carried on one side of the numeral wheel and radially displaced from the axis of the latter, a lever having an end shaped to form a pair of noses either one of which can engage the projection and rotate the numeral wheel into the zero position wherein the other nose may also engage the said projection, means for imparting step by step advance movements to the numeral wheel, a spring controlled detent for preventing retrograde movements of the numeral wheel, and means for effecting release of the numeral wheel by both the advancing means and said detent and for then eiecting movement of the lever to cause zeroizing to be effected by said noses.

4. In a taximeter, the combination of a numeral wheel, a projection carried on one side of the numeral wheel and radially displaced from the axis of the latter, a lever having an end shaped to form a pair of noses either one of which can engage the projection and rotate the numeral wheel into the zero position wherein the other nose may also engage the said projection, means for imparting step by step advance move-- ments to the numeral wheel, a spring controlled detent for preventing retrograde movements of the numeral wheel, and a cam for effecting in sequence, Iirst, release of the numeral wheel by both the advancing means and said detent, and, second, movement of the lever to cause zeroizing to he eected by said noses.

5. In a taximeter, the combination of a numeral wheel, a projection carried on one side of the numeral wheel and radially displaced from the axis of the latter, a lever having an end shaped to form a pair of noses either one of which can engage the projection and rotate the numeral wheel into zero position wherein the other nose may also engage the said projection, means for imparting step by step advance movements to the numeral wheel, a spring controlled detent for preventing retrograde movements of the numeral wheel, and means for effecting release of the numeral wheel by both the advancing means and said detent and for then eectng yielding movement of the lever to cause zeroizing to be eilected by said noses.

6. In a taximeter, the combination of a numeral wheel, a roller carried on one side of the numeral wheel and radially displaced from the axis of the latter, a manually rotatable spindle, a cam on said spindle, and a spring urged lever engageable with said cam and having one end shaped to form a pair of noses so that on rotation of the cam by the spindle the lever is released and is swung by its spring to engage one of its noses with the roller aforesaid whereby the numeral wheel is rotated into the zero position wherein the other nose also engages the roller.

'7. In a taximeter, the combination of a numeral wheel, means for intermittently rotating said numeral wheel, a roller carried on one side of said numeral wheel and radially displaced from the axis of the latter, a manually rotatable spindle, a cam on said spindle, a spring urged lever engageable with said cam and having one end shaped to form a pair of noses, one of said noses being arranged to engage the roller, on release of the lever by the cam, so as to rotate the numeral wheel into the zero position wherein the other nose also engages the roller, and a second lever engageable with said cam and operable, immediately before the release of the rstmentioned lever, to disconnect the numeral wheel rotating means from the numeral wheel.

CHRISTOPHER FREDERICK WEBB.

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